temperature: added C sources and removed grove dependency

Signed-off-by: Mihai Tudor Panu <mihai.tudor.panu@intel.com>

src/temperature/temperature.c

@@ -0,0 +1,77 @@
+/*
+ * Author: Sisinty Sasmita Patra <sisinty.s.patra@intel.com>
+ *
+ * Copyright (c) 2016 Intel Corporation.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include "temperature.h"
+#include "upm.h"
+
+temperature_context temperature_init(int pin)
+{
+    temperature_context dev =
+      (temperature_context)malloc(sizeof(struct _temperature_context));
+
+    if (dev == NULL) return NULL;
+
+    dev->aio = mraa_aio_init(pin);
+    if(dev->aio == NULL)
+    {
+        free(dev);
+        return NULL;
+    }
+
+    dev->m_aRes = (1 << mraa_aio_get_bit(dev->aio));
+
+    return dev;
+}
+
+void temperature_close(temperature_context dev)
+{
+    mraa_aio_close(dev->aio);
+    free(dev);
+}
+
+upm_result_t temperature_get_value(temperature_context dev,
+                                   float* tempval)
+{
+    float val = 0.0;
+    val = (float)mraa_aio_read(dev->aio);
+
+    if (val == -1.0)
+    {
+        return UPM_ERROR_OPERATION_FAILED;
+    }
+
+    // From old C++ UPM code, needs rework!!!
+    float r = ((float)dev->m_aRes - val) * 10000.0 / val;
+    float t = 1.0 / (log(r / 10000.0) / 3975.0 + 1.0 / 298.15) -273.15;
+
+    // Celsius
+    *tempval = t;
+
+    return UPM_SUCCESS;
+}